RE:Seattle trip 10/11-10/13
If you're looking for trout, check out the below link. These guys are right on the river and post reliable Yakima River fishing reports. There isn't much bank fishing, tho, so you need to either go with someone who has a raft/driftboat or do a guided trip.
The other option is summer steelhead fishing. Tackle is a bit different, but you have the chance of hooking up in most all of the rivers around Seattle. Dennis Dickson is very good with new steelheaders and provides all the necessary gear. He guides on the North Fork Stillaguamish and Skykomish rivers in the summer and can be reached at the link below.
I wish I could take a few days to show you around, but it looks like I'm going to be out of town during that period of time. Drop me an email just before you're heading out - if I am still here, I'd be happy to show you around. As Juro mentioned, the Reiter area at dawn and Snoqualmie are two spots that are often good for steelhead in August. Haven't heard from Sinktip lately - maybe he'd be up for a mini-clave?